Many routine laboratory tests have been developed to the stage where they can be performed by automation. This is an advantage in areas such as clinical testing where automation can profitably be used to free technicians for other tasks, and where automation insures a more accurate analysis than was previously possible by reducing the human error involved. This trend towards automation has led to the development of a number of completely automatic analytic instruments, which are now in use, primarily in clinical areas and primarily for analyzing reaction rates in fluids.
The most fully automatic of these instruments are, with rare exception, principally sampling systems where ingenious methods are employed to remove the fluid to be tested from its container and to deliver it to a cuvette, where it is mixed with the proper reagents. The cuvette is then positioned in the analysis stage, and the fluid in it analyzed by conventional means. In one such instrument the sample fluid and reagents are supplied to the cuvette through a single tube by the pumping action of a proportional pump. The different fluids are separated from one another by air bubbles, which also act as a means for cleansing the tube so that the fluids will not become contaminated. In another instrument the fluid to be analyzed is deposited on a porous tape, and the reagents are supplied from another porous tape by bringing the two into contact from a specified time interval. The tape is then used to present the mixture to the analysis stage.
The present invention is an integrated instrument, based on the use of a deformable test pack. It incorporates not only a system for sampling the test fluid and introducing it without contamination into the test pack, but also various other preparational and operational stages through which the sample cell proceeds until the analysis is complete. It is designed to be fully automatic and, therefore, unusually simple to run; to allow easy selection of the type, number, and order of analysis performed on each sample; and to be immediately operable without waste of time or material in startup or shutdown. The entire reaction and analysis of that reaction takes place in a sealed test pack which is identified upon entering the instrument. The test results are converted automatically to the proper units, and are printed on a separate report sheet for each sample.
Certain of the elements of the instrument such as the deformable test pack, the sampling system, and the photometric system, which are of broad application, are the subject of separate patent applications, mentioned above. The instant invention is concerned with those novel aspects of the instrument which make it a fully automatic, integrated analysis system. It is concerned with the way in which the test pack is presented to the sampling system, in such manner that future operations upon the test pack are predetermined from that stage on, and with the way in which the test pack is transported from the filling stage, through various preparational and operational stages, to the analysis stage and from there to disposal.
The advantages of the instrument are to be found in the fact that since the sample fluid is contained along with the reagents in a closed test pack, the possibility of contamination is reduced, as is the possibility of confusion due to improper test identification. The sample and test are positively identified, on the test pack, and the type of tests to be run can be readily interchanged. Cleansing is no longer a problem since the test pack is inexpensive enough to be disposable; and, since the test pack is deformable, preparation and analysis of the fluid contained therein is particularly easy.